Sassafras

Sassafras, found mostly in the eastern United States, is characterized by its' three distinct leaves on the same tree - unlobed or oval (top left); bilobed or mitten-shaped (top right); and trilobed (bottom). If you've living in New York City like I do, you can find it in Prospect Park. Root beer was originally made from sassafras until the FDA banned it in the late 1960s as a potential carcinogen, but no human studies have ever been made and many believe the ban to be unwarranted. (Read more about that here.)
The roots of a sassafras sapling can be uprooted and used to make a damn good tea - it tastes just like root beer - so next time you're out east and want something other than pine needle tea, look around for some sassafras. It won't hurt you.